Files
astaroth/acc/mhd_solver/stencil_process.sps
2019-06-14 14:19:07 +03:00

266 lines
6.8 KiB
Scheme

#define LINDUCTION (1)
#define LENTROPY (1)
#define LTEMPERATURE (0)
#define LGRAVITY (0)
// Declare uniforms (i.e. device constants)
uniform Scalar cs2_sound;
uniform Scalar nu_visc;
uniform Scalar cp_sound;
uniform Scalar cv_sound;
uniform Scalar mu0;
uniform Scalar eta;
uniform Scalar gamma;
uniform Scalar zeta;
uniform int nx_min;
uniform int ny_min;
uniform int nz_min;
uniform int nx;
uniform int ny;
uniform int nz;
Vector
value(in Vector uu)
{
return (Vector){value(uu.x), value(uu.y), value(uu.z)};
}
Matrix
gradients(in Vector uu)
{
return (Matrix){gradient(uu.x), gradient(uu.y), gradient(uu.z)};
}
Scalar
continuity(in Vector uu, in Scalar lnrho) {
return -dot(value(uu), gradient(lnrho)) - divergence(uu);
}
#if LENTROPY
Vector
momentum(in Vector uu, in Scalar lnrho, in Scalar ss, in Vector aa) {
const Matrix S = stress_tensor(uu);
const Scalar cs2 = cs2_sound * exp(gamma * value(ss) / cp_sound + (gamma - 1) * (value(lnrho) - LNRHO0));
const Vector j = (Scalar(1.) / mu0) * (gradient_of_divergence(aa) - laplace_vec(aa)); // Current density
const Vector B = curl(aa);
const Scalar inv_rho = Scalar(1.) / exp(value(lnrho));
// Regex replace CPU constants with get\(AC_([a-zA-Z_0-9]*)\)
// \1
const Vector mom = - mul(gradients(uu), value(uu))
- cs2 * ((Scalar(1.) / cp_sound) * gradient(ss) + gradient(lnrho))
+ inv_rho * cross(j, B)
+ nu_visc * (
laplace_vec(uu)
+ Scalar(1. / 3.) * gradient_of_divergence(uu)
+ Scalar(2.) * mul(S, gradient(lnrho))
)
+ zeta * gradient_of_divergence(uu);
return mom;
}
#elif LTEMPERATURE
Vector
momentum(in Vector uu, in Scalar lnrho, in Scalar tt) {
Vector mom;
const Matrix S = stress_tensor(uu);
const Vector pressure_term = (cp_sound - cv_sound) * (gradient(tt) + value(tt) * gradient(lnrho));
mom = -mul(gradients(uu), value(uu)) -
pressure_term +
nu_visc *
(laplace_vec(uu) + Scalar(1. / 3.) * gradient_of_divergence(uu) +
Scalar(2.) * mul(S, gradient(lnrho))) + zeta * gradient_of_divergence(uu);
#if LGRAVITY
mom = mom - (Vector){0, 0, -10.0};
#endif
return mom;
}
#else
Vector
momentum(in Vector uu, in Scalar lnrho) {
Vector mom;
const Matrix S = stress_tensor(uu);
// Isothermal: we have constant speed of sound
mom = -mul(gradients(uu), value(uu)) -
cs2_sound * gradient(lnrho) +
nu_visc *
(laplace_vec(uu) + Scalar(1. / 3.) * gradient_of_divergence(uu) +
Scalar(2.) * mul(S, gradient(lnrho))) + zeta * gradient_of_divergence(uu);
#if LGRAVITY
mom = mom - (Vector){0, 0, -10.0};
#endif
return mom;
}
#endif
Vector
induction(in Vector uu, in Vector aa) {
// Note: We do (-nabla^2 A + nabla(nabla dot A)) instead of (nabla x (nabla
// x A)) in order to avoid taking the first derivative twice (did the math,
// yes this actually works. See pg.28 in arXiv:astro-ph/0109497)
// u cross B - ETA * mu0 * (mu0^-1 * [- laplace A + grad div A ])
const Vector B = curl(aa);
const Vector grad_div = gradient_of_divergence(aa);
const Vector lap = laplace_vec(aa);
// Note, mu0 is cancelled out
const Vector ind = cross(value(uu), B) - eta * (grad_div - lap);
return ind;
}
#if LENTROPY
Scalar
lnT( in Scalar ss, in Scalar lnrho) {
const Scalar lnT = LNT0 + gamma * value(ss) / cp_sound +
(gamma - Scalar(1.)) * (value(lnrho) - LNRHO0);
return lnT;
}
// Nabla dot (K nabla T) / (rho T)
Scalar
heat_conduction( in Scalar ss, in Scalar lnrho) {
const Scalar inv_cp_sound = AcReal(1.) / cp_sound;
const Vector grad_ln_chi = - gradient(lnrho);
const Scalar first_term = gamma * inv_cp_sound * laplace(ss) +
(gamma - AcReal(1.)) * laplace(lnrho);
const Vector second_term = gamma * inv_cp_sound * gradient(ss) +
(gamma - AcReal(1.)) * gradient(lnrho);
const Vector third_term = gamma * (inv_cp_sound * gradient(ss) +
gradient(lnrho)) + grad_ln_chi;
const Scalar chi = AC_THERMAL_CONDUCTIVITY / (exp(value(lnrho)) * cp_sound);
return cp_sound * chi * (first_term + dot(second_term, third_term));
}
Scalar
heating(const int i, const int j, const int k) {
return 1;
}
Scalar
entropy(in Scalar ss, in Vector uu, in Scalar lnrho, in Vector aa) {
const Matrix S = stress_tensor(uu);
const Scalar inv_pT = Scalar(1.) / (exp(value(lnrho)) * exp(lnT(ss, lnrho)));
const Vector j = (Scalar(1.) / mu0) * (gradient_of_divergence(aa) - laplace_vec(aa)); // Current density
const Scalar RHS = H_CONST - C_CONST
+ eta * (mu0) * dot(j, j)
+ Scalar(2.) * exp(value(lnrho)) * nu_visc * contract(S)
+ zeta * exp(value(lnrho)) * divergence(uu) * divergence(uu);
return - dot(value(uu), gradient(ss))
+ inv_pT * RHS
+ heat_conduction(ss, lnrho);
}
#endif
#if LTEMPERATURE
Scalar
heat_transfer(in Vector uu, in Scalar lnrho, in Scalar tt)
{
const Matrix S = stress_tensor(uu);
const Scalar heat_diffusivity_k = 0.0008; //8e-4;
return -dot(value(uu), gradient(tt)) + heat_diffusivity_k * laplace(tt) + heat_diffusivity_k * dot(gradient(lnrho), gradient(tt)) + nu_visc * contract(S) * (Scalar(1.) / cv_sound) - (gamma - 1) * value(tt) * divergence(uu);
}
#endif
// Declare input and output arrays using locations specified in the
// array enum in astaroth.h
in Scalar lnrho = VTXBUF_LNRHO;
out Scalar out_lnrho = VTXBUF_LNRHO;
in Vector uu = (int3) {VTXBUF_UUX, VTXBUF_UUY, VTXBUF_UUZ};
out Vector out_uu = (int3) {VTXBUF_UUX,VTXBUF_UUY,VTXBUF_UUZ};
#if LINDUCTION
in Vector aa = (int3) {VTXBUF_AX,VTXBUF_AY,VTXBUF_AZ};
out Vector out_aa = (int3) {VTXBUF_AX,VTXBUF_AY,VTXBUF_AZ};
#endif
#if LENTROPY
in Scalar ss = VTXBUF_ENTROPY;
out Scalar out_ss = VTXBUF_ENTROPY;
#endif
#if LTEMPERATURE
in Scalar tt = VTXBUF_TEMPERATURE;
out Scalar out_tt = VTXBUF_TEMPERATURE;
#endif
Kernel void
solve(Scalar dt) {
out_lnrho = rk3(out_lnrho, lnrho, continuity(uu, lnrho), dt);
#if LINDUCTION
out_aa = rk3(out_aa, aa, induction(uu, aa), dt);
#endif
#if LENTROPY
out_uu = rk3(out_uu, uu, momentum(uu, lnrho, ss, aa), dt);
out_ss = rk3(out_ss, ss, entropy(ss, uu, lnrho, aa), dt);
#elif LTEMPERATURE
out_uu =rk3(out_uu, uu, momentum(uu, lnrho, tt), dt);
out_tt = rk3(out_tt, tt, heat_transfer(uu, lnrho, tt), dt);
#else
out_uu = rk3(out_uu, uu, momentum(uu, lnrho), dt);
#endif
}